The utility of optoelectronic couplers has long been recognized, and various packaging schemes have been utilized for permanently juxtaposing an optical emitter and an optical sensor in order to provide electrical isolation between two or more electrical circuit paths in the coupler-isolator mode. Alternative package configurations comprise slots for interrupting the optical path (the slotted mode) or orienting the optical path of each device to a common external point where a reflector completes the optical path between the devices (the reflective mode). Such alternative packages are useful for example in position-sensitive trigger circuits.
Because of the multiplicity of user-required operating modes for optoelectronic couplers and because of the variety of devices which may be used for either the emitter or the sensor, a large inventory of package types is required to provide a variety of functions where dedicated packaging is used in the sense that both the individual devices and the mode are chosen a priori.
It is an object of the present invention to provide a housing for an optoelectronic pair which allows operation in at least two modes.
It is a further object of the invention to provide an optoelectronic coupler housing which allows the use of a separately-packaged emitter and detector.
It is yet a further object of the invention to provide a housing which allows replacement of either or both the optoelectronic devices.
In a housing in accordance with the present invention, a sensor and an emitter are semi-permanently juxtaposed to permit their use as a coupler-isolator or as a sensor operating in either the slotted or reflective modes. The individual, discretely-packaged, optoelectronic elements use standard packaging for minimum cost, and the housing constitutes a separate standard package for the optical pair. The emitter-sensor pair is oriented within the opaque housing to provide two non-collinear optical paths.